Chain A ( H27 V28 D29 C67 I68 T69 G101 H102 V103 D104 F105 E127 C130 V131 Q132 T135 G524 E525 L526 H527 Y719 L720 V721 D722 I723 S724 C725 V729 V733 L762 S767 F770 T771 L774 R775 T778 G780 Q781 A782 F783 P784 Q785 C786 V787 )